13 - STI Flashcards
What are the common STI presentations?
- Asymptomatic
- Urethritis
- Cervicitis
- Genital ulcer disease
- Prostatitis
- Pelvic inflammatory disease (PID)
- Vaginal discharge
What are the most common STIs?
Gonorrhea, chlamydia, and syphilis
What are some common co-infections?
- Gonorrhea w/ chlamydia
- Syphilis w/ HIV (especially in MSM)
What are some risk factors for STIs?
- Unaware/ lack of knowledge (from either pt or Dr.)
- Gender (female > male generally)
- Unprotected or anonymous sex
- Sexual contact w/ infected person
- # of sexual partners
- MSM
- Age, socioeconomic, societal stigma
- Co-infection
- Asymptomatic or missed sx
What is included in a clinical work-up for STIs?
- Presentation, history, travel, contacts
- Lab tests including HIV test (if pt consents)
- Public health notification and contact tracing
- Tx, follow-up, and counselling
What are some complications of STIs?
- Pelvic inflammatory disease (1/3 attributed to gonorrhea and/or chlamydia)
- Risk of cervical cancer
- Damage to reproductive tract
What are the common age groups for the most common STIs?
- Chlamydia and gonorrhea = females 15-24; males 20-29
- Syphilis = females 25-39; males 20-24 and 30-39
Do females or males have higher rates of infection for gonorrhea, chlamydia, and syphilis?
- Gonorrhea and chlamydia = females
- Syphilis = males
What is some pt education that you can provide about STIs?
- Risk of re-infection and of untreated infection
- Abstain from sex at least 3 days after tx completed
- Barrier protection for at least 7 days; recommend as much as possible
- Reduce risks of sexual activity
- Return to care if sx not improved
- Testing
What causes gonorrhea?
- Neisseria gonorrhoeae (gram neg diplococci)
- Exclusive human pathogen
What are the most common sites of infection of gonorrhea and some other possible sites?
- Most common = urethritis, cervicitis
- Other = oropharynx, disseminated gonococcal infection (DGI), neonatal conjunctivitis
Common sx of gonorrhea
- Purulent urethral or rectal discharge
- Abnormal vaginal discharge or uterine bleeding
What is disseminated gonorrhea infection? Symptoms?
- When N. gonorrhoeae bacteremia seeds at sites outside of reproductive tract
- Sx = fever, chills, joint pain/ swelling, skin rash
What should be considered for pregnant women w/ gonorrhea?
- Choice of medication
- Risk of transmission
- Neonatal prophylaxis
How is gonorrhea diagnosed?
- Sx and history
- Lab (gram stain; urine, cervix, or urethra culture; NAAT)
What are some tx issues w/ gonorrhea?
- Emergence of antibiotic resistance
- Increased tx failure and concern w/ superbug
- Loss of penicillin, ampicillin, and FQs
- Treat px for both gonorrhea and chlamydia
What is the tx for uncomplicated anogenital or pharyngeal gonorrhea infection in adults and youth >/ 9 y/o?
- Ceftriaxone 250 mg IM [Cefixime 800 mg PO] x 1 dose + azithro 1 g PO x 1 dose
- [Azithro 2 g PO x 1 dose]
What is the tx for uncomplicated gonorrhea in children < 9 y/o? What is the difference for anogenital or pharyngeal infection?
- Cefixime 8 mg/kg (max 400 mg) PO BID x 2 doses + azithro 20 mg/kg (max 1 g) PO x 1 dose **preferred for anogenital
- Ceftriaxone 50 mg/kg (max 250 mg) IM x 1 dose + azithro **preferred for pharyngeal
- Ceftriaxone 25-50 mg/kg (max 125 mg/dose) recommended for neonates
What is the tx for disseminated arthritis gonococcal infection in px > 1 m/o?
- Ceftriaxone IV/IM daily x 7 days + azithro PO x 1 dose
- Ceftriaxone = 2 g for 9 years and older; 50 mg/kg (max 1 g) for 1 month - 9 y/o
- Azithro = 1 g for 9 years and older; 20 mg/kg (max 1 g) for 1 month - 9 y/o
How do the treatment of disseminated gonococcal infection change for meningitis, endocarditis, or opthalmia?
- Meningitis = duration 10-14 days and hospitalization indicated
- Endocarditis = duration 28 days
- Ophthalmia = 1 dose of each ceftriaxone and azithro
What is the tx for anogenital gonorrhea w/ cephalosporin-resistance or anaphylaxis to penicillin or cephalosporin?
- Azithro 2 g x 1 dose + gentamicin 240 mg
- Gent can be given IM as 2 separate injections or IV infused over 30 mins
What is the tx for anogenital gonorrhea w/ macrolide-resistance or anaphylaxis to macrolides or cephalosporin?
- Gentamicin 240 mg + doxycyline 100 mg x 7 days
- Gent can be given IM as 2 separate injection or IV infused over 30 mins
When should follow-up occur for gonorrhea infections?
- All pharyngeal infections
- Case treated w/ regimen other than preferred regimen
- Documented antimicrobial resistance
- Infection during pregnancy
- Children
What are sx of PID?
- Endometriosis, salpingitis (inflammation of fallopian tubes) and pelvic peritonitis
- Lower abdominal/mild pelvic pain
- Increased vaginal discharge
- Irregular menstrual bleeding
- Painful & frequent urination
- Abdominal, pelvic organ, uterine tenderness
Complications of PID
- Tubo-ovarian abscess
- Infertility
- Ectopic pregnancy
- Chronic pelvic pain
Diagnosis of PID
Combination of signs & sx & gonorrhea/chlamydia positive
Outpatient tx for PID
- Ceftriaxone 250 mg IM x 1 dose + doxy 100 mg PO x 14 days +/- metro 500 mg PO BID x 14 days
- [Azithro 250 mg PO daily x 1 week]
Cause of chlamydia
Chlamydia trachomatis (gram neg, obligate intracellular pathogen)
Sx of chlamydia
- Men = mild dysuria, discharge, rectal pain/discharge/bleeding
- Women = dysuria/frequency uncommon, abnormal vaginal discharge or uterine bleeding
Special considerations for pregnant women w/ chlamydia
- Should receive chlamydia test at 1st prenatal visit
- Test for other STIs if chlamydia positive
Special considerations for newborns w/ chlamydia
- 2/3 acquire infection from mother via endocervical exposure
- Can cause neonatal conjunctivitis or pneumonia
Diagnosis of chlamydia
- Sx & history
- Lab – NAAT (urine, eye, cervical); DFA/direct fluorescent antigen (throat, rectal, nasopharyngeal, pulmonary, eye); culture if tx failure
Tx for uncomplicated anogenital chlamydia infection?
- Azithro 1 g PO x 1 dose (for 1 m/o - 9 y/o dose is 12-15 mg/kg max 1 g)
- [Doxy 100 mg BID x 7 days] only for > 9 y/o
Tx for pregnant women w/ urethral, endocervical, or rectal chlamydia infection?
- Erythro 500 mg PO QID x 7 days
- [Amox 500 mg PO TID x 7 days]
Cause of syphilis
- Treponema pallidum
- Exclusively human disease; invades through mucous membranes or open lesions
Describe the stages of syphilis infection. Why is it important to know the stage the pt is in?
- Primary – occurs on genitalia, perianal, mouth & throat; incubation = 3 weeks
- Secondary – multi-system; rash, fever, malaise, headaches; incubation = 2-12 weeks
- Latent – multi-system (dormant); asymptomatic; early < 1 year, late = 1 year or more
- Tertiary – CV = 10-30 years; neurosyphilis (CNS, eyes) = < 2 years – 20 years; gumma (tissue destruction of any organ) = 1-46 years (most cases 15 years)
- Important for management of cases and contacts
Special considerations for pregnant women w/ syphilis
- Screen for STIs at first prenatal visit, preferably 1st trimester
- For high-risk women, screen at 28-32 weeks and again at delivery
Special considerations for newborns w/ syphilis
- Fetal risk highest when mom primary/secondary syphilis
- Screen newborn if signs or sx of early congenital syphilis
Diagnosis of syphilis
- History & clinical presentation
- Lab (difficult to grow) = dark field microscopy, NAAT, serologic
Tx for syphilis in non-pregnant adults. What is the difference between a pt in primary, secondary, or early latent (< 1 year) and a pt in late latent, unknown latent, or other tertiary not involving NS?
- Benzathine penicillin G 2.4 MU IM
- Primary, secondary, or early latent = 1 dose
- Late latent, unknown latent, or tertiary = weekly x 3 doses
Cause of trichomoniasis
- Trichomonas vaginalis
- Humans are only host & can only be spread through sexual contact (non-venereal infection uncommon/rare)
Sx of trichomoniasis
- Male = asymptomatic, urethral discharge, dysuria
- Female = asymptomatic, malodorous vaginal discharge & pruritus (worse during menses), dysuria
Tx for trichomoniasis. How can efficacy be increased?
- Metronidazole 2 g PO x 1 dose OR 500 mg PO BID x 7 days
- Efficacy increases if partner also treated
Special consideration for trichomoniasis in pregnancy
- May be associated w/ premature rupture of membrane, preterm birth, & low birth weight
- Metronidazole not CI in pregnancy or breastfeeding
